传热系数自动调节墙体传热机理研究
发布时间：2018-11-08 15:59
【摘要】：传统墙体传热系数固定不变,不利于昼夜温差较大地区的建筑及时利用室外空气加热或冷却室内空气。为了更好的利用这些地区的室外空气作为建筑冷却/加热的自然冷/热源,减少建筑能耗,本文提出了传热系数随室外温度变化的墙体的理念。该墙体的特点是根据室外温度的变化自动调节自身传热系数,增加对室内热环境的"有益"传热,减少"有害"传热。其节能的本质是对室外空气中蕴含能量的利用。本文分析了变传热系数墙体的工作原理,给出了这一墙体的实现形式。同时设计、搭建了传热性能测试实验台,对墙体传热系数调节层的传热性能进行了测试和分析。实验分析了传热系数调节层的加热温度分别为30℃、40℃和50℃时,调节层中充水高度占调节层总高度的百分数为0%(调节层中为全空气传热工况)、25%、50%、75%和100%(调节层中为全水传热工况)的工况下,通过传热系数调节层的传热温差和热流密度的变化关系及其对调节层传热系数的影响。实验结果表明:调节层加热稳定温度温为30°℃时,随着调节层充水高度的增加,其等价导热系数变化范围为0.024-0.102W/m·K;40°℃时,其等价导热系数变化范围为0.026-0.127W/m·K;50℃时,等价导热系数变化范围为 0.038-0.180 W/m·K。同一加热温度时高、低热阻工况下等价导热系数的变化倍数可达4-5倍。建立了变传热系数墙体传热的数学模型,并根据模型计算分析了腔体厚度δ变化时的传热特性和充水高度对其传热系数的影响。计算表明:腔体的等价导热系数随着腔体厚度的增大而增大。当腔体厚度δ的变化范围为0.003-0.039m时,随着腔体充水高度增加,高热阻工况(全空气传热工况)时的等价导热系数λe的变化范围为0.048-0.336W/m·K;低热阻工况(全水传热工况)时的等价导热系数λe的变化范围为0.655-12.641 W/m·K。腔体高、低热阻工况下的等价导热系数变化倍数可达2-35倍。同时分析了我国不同气候分区典型城市冬、夏季应用变传热系数墙体的节能潜力,计算表明:在各地区室外气象参数条件下,变传热系数墙体为围护结构时,建筑冬、夏季所需的供热量、制冷量比一般保温材料墙体低,在夏季其节能效果更加显著,其中哈尔滨、兰州和昆明地区夏季使用变传热系数墙体的节能率ηt分别可高达66%、59%和54%。最后本文给出了传热系数调节层的其他可能的结构形式,以及此墙体与日光温室滴灌系统相结合的应用形式。
[Abstract]:The traditional wall heat transfer coefficient is fixed, which is unfavorable for the buildings in the regions with large diurnal temperature difference to use outdoor air to heat or cool the indoor air in time. In order to make better use of outdoor air in these areas as the natural cooling / heat source of building cooling / heating and reduce building energy consumption, this paper puts forward the idea of wall with the change of heat transfer coefficient with outdoor temperature. The characteristic of the wall is to adjust its heat transfer coefficient automatically according to the change of outdoor temperature, to increase the "beneficial" heat transfer to the indoor thermal environment and to reduce the "harmful" heat transfer. The essence of energy saving is the use of energy in outdoor air. In this paper, the working principle of variable heat transfer coefficient wall is analyzed, and the realization form of this wall is given. At the same time, the test bench of heat transfer performance is designed and built, and the heat transfer performance of the regulating layer of wall heat transfer coefficient is tested and analyzed. When the heating temperature of the regulating layer with heat transfer coefficient is 30 鈩，
本文编号：2318964
[Abstract]:The traditional wall heat transfer coefficient is fixed, which is unfavorable for the buildings in the regions with large diurnal temperature difference to use outdoor air to heat or cool the indoor air in time. In order to make better use of outdoor air in these areas as the natural cooling / heat source of building cooling / heating and reduce building energy consumption, this paper puts forward the idea of wall with the change of heat transfer coefficient with outdoor temperature. The characteristic of the wall is to adjust its heat transfer coefficient automatically according to the change of outdoor temperature, to increase the "beneficial" heat transfer to the indoor thermal environment and to reduce the "harmful" heat transfer. The essence of energy saving is the use of energy in outdoor air. In this paper, the working principle of variable heat transfer coefficient wall is analyzed, and the realization form of this wall is given. At the same time, the test bench of heat transfer performance is designed and built, and the heat transfer performance of the regulating layer of wall heat transfer coefficient is tested and analyzed. When the heating temperature of the regulating layer with heat transfer coefficient is 30 鈩，
本文编号：2318964
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